Field of the Invention
The present invention relates to an information processing apparatus, information processing method, and computer-readable storage medium which perform sound source separation and noise prevention.
Description of the Related Art
Digital video cameras and, recently, even digital cameras are capable of capturing moving images, and this increases opportunities for simultaneously recording sounds. Since it is difficult to check a recorded sound during image capturing, it is sometimes found when the sound is played back after image capturing that noise is mixed or a sound of interest is hidden behind another loud sound. Accordingly, techniques of separating a target sound from unnecessary sound components and reducing a noise component have been proposed.
For example, a beamformer is known as a technique of processing a plurality of microphone signals by using directionality information of an sound source, thereby extracting a target sound by emphasizing it, or preventing a non-target sound (see Futoshi Asano, “Array Signal Processing of Sound-Sound Source Locallization•Tracking and Separation-”, Acoustic Technology Series 16, CORONA, 2011, Feb. 25, pp. 70-105). Also, as a method of reducing wind noise mixed during image capturing, an arrangement which performs non-negative matrix factorization on a plurality of acoustic signals recorded parallel has been proposed (see Japanese Patent Laid-Open No. 2011-227417). In this arrangement, of a plurality of bases of a basis matrix of a first acoustic signal, a basis having a high correlation with a basis of a basis matrix of a second acoustic signal is specified as a noise basis corresponding to a noise component of the first acoustic signal, and the noise component of the first acoustic signal is suppressed based on this noise basis.
The above-mentioned conventional arrangement performs signal processing by inputting audio signals of a plurality of channels. However, some recording apparatuses such as digital cameras have only one microphone. The above-mentioned arrangement using a plurality of microphone signals cannot be applied to sounds recorded by a recording apparatus like this. This makes it impossible to separate unnecessary sounds or reduce unsteady noise such as wind noise.